Greater Manchester Police caught 240 motorists after new legislation made it easier for officers to detect drugged-up drivers.
Legal limits were introduced on 2 March 2015 for 17 legal and illegal drugs.
And new roadside testing kits made it possible for officers to test motorists for cannabis or cocaine using a saliva sample.
Between March and December 2015, police arrested 365 drug drivers and 240 tested positive.
Inspector Susan Redfern from the Road Policing Unit, said: “Officers are more equipped than ever to catch drug drivers and in the last year we’ve detected and prosecuted more people than ever.
“Drug driving is just as dangerous as drink driving and anybody getting behind the wheel under the influence of drugs is putting themselves and others at serious risk.
“Tackling this type of crime remains a priority for police but we also need the public to help us by taking greater responsibility for their own behaviour and challenging others.
“Our message is simple – if you are driving then no amount of drugs or alcohol is safe. Have none for the road, or arrange another way to get home.”
To report a drug driver please call Greater Manchester Police on 101 or Crimestoppers anonymously on 0800 555 111. In an emergency when a drug driver poses an immediate threat to themselves or others, please dial 999.
